The Cancer and Leukemia Group B (CALGB) Statistical Center located at Duke University has primary responsibility for all statistical, data management, computing, and related activities for the CALGB. Faculty and staff statisticians and data coordinators collaborate closely with study chairs, committee chairs, and other investigators on the design, conduct, analysis, and reporting of all clinical trials and other studies conducted by the CALGB. The Statistical Center has responsibility for central data quality control and database administration. All clinical data are sent to the Statistical Center for editing, verification, and entry into the official CALGB database. Scientific laboratory data are transmitted electronically and become part of the official record. Statisticians and data coordinators from the Statistical Center are assigned to each CALGB study. They work closely with study chairs to monitor the studies and to prepare all necessary reports, analyses, and manuscripts.